call letters definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
the letters, and sometimes the numbers, that identify a radio or TV transmitting station
call letters definition by American Heritage Dictionary
The identifying code letters or numbers of a radio or television transmitting station, assigned by a regulatory body. Also called call sign.